Classified funds are divided into two types of shares according to the basic share of the fund, one is the part with low expected risk and return and priority in income distribution, which is called "Class A share" here, and the other is the part with high expected risk and return and secondary priority in income distribution, which is called "Class B share" here. Class a shares have the characteristics of guaranteed capital and guaranteed income; Class B stocks have the characteristics of leverage to amplify risks and returns.